Simulating Male Selfish Strategy in Reproduction Dispute

We introduce into the Penna Model for biological ageing one of the possible male mechanisms used to maximize the ability of their sperm to compete with sperm from other males. Such a selfish mechanism increases the male reproduction success but may decrease the survival probability of the whole female population, depending on how it acts. We also find a dynamic phase transition induced by the existence of an absorbing state where no selfish males survive.Comment: 7 pages, latex including 2 eps figure

The mechanism for the electrooxidation of procarbazine pharmaceutical preparation in alkaline media and its mathematical description

The mechanism for the electrooxidation of procarbazine in alkaline media has been proposed. The process is realized completely on the electrode surface and is adsorption-controlled. The oscillatory behavior in this case is more probable, than for neutral media and may be caused by influences of electrochemical oxidation and salt dissolution from the electrode surface

Bifurcations and Averages in the Homoclinic Chaos of a Laser with a Saturable Absorber

The dynamical bifurcations of a laser with a saturable absorber were calculated, with the 3-2 level model, as function of the gain parameter. The average power of the laser is shown to have specific behavior at bifurcations. The succession of periodic-chaotic windows, known to occur in the homoclinic chaos, was studied numerically. A critical exponent of 1/2 is found on the tangent bifurcations from chaotic into periodic pulsations.Comment: 6 or 7 pages, 3 figures, publishe

Relativistic quantum dynamics of scalar bosons under a full vector Coulomb interaction

The relativistic quantum dynamics of scalar bosons in the background of a full vector coupling (minimal plus nonminimal vector couplings) is explored in the context of the Duffin-Kemmer-Petiau formalism. The Coulomb phase shift is determined for a general mixing of couplings and it is shown that the space component of the nonminimal coupling is a {\it sine qua non} condition for the exact closed-form scattering amplitude. It follows that the Rutherford cross section vanishes in the absence of the time component of the minimal coupling. Bound-state solutions obtained from the poles of the partial scattering amplitude show that the time component of the minimal coupling plays an essential role. The bound-state solutions depend on the nonminimal coupling and the spectrum consists of particles or antiparticles depending on the sign of the time component of the minimal coupling without chance for pair production even in the presence of strong couplings. It is also shown that an accidental degeneracy appears for a particular mixing of couplings.Comment: 8 pages, 1 table. arXiv admin note: text overlap with arXiv:1403.603

Estimativa do custo de produção de café agroecológico no Município de Alto Paraíso - Rondônia.

Considerando a necessidade de se gerar informações socioeconômicas que contribuam para o delineamento de agroecossistemas sustentáveis, objetivo deste trabalho é a determinação do custo de produção do café robusta em sistema agroecológico no Município de Alto Paraíso, Rondônia. Pretende-se ainda determinar a renda auferida por uma unidade de produção típica do sistema café-mel-madeira.bitstream/item/24715/1/cot317-cafeagroecologico.pd

Efficient Formal Verification for the Linux Kernel

Formal verification of the Linux kernel has been receiving increasing attention in recent years, with the development of many models, from memory subsystems to the synchronization primitives of the real-time kernel. The effort in developing formal verification methods is justified considering the large code-base, the complexity in synchronization required in a monolithic kernel and the support for multiple architectures, along with the usage of Linux on critical systems, from high-frequency trading to self-driven cars. Despite recent developments in the area, none of the proposed approaches are suitable and flexible enough to be applied in an efficient way to a running kernel. Aiming to fill such a gap, this paper proposes a formal verification approach for the Linux kernel, based on automata models. It presents a method to auto-generate verification code from an automaton, which can be integrated into a module and dynamically added into the kernel for efficient on-the-fly verification of the system, using in-kernel tracing features. Finally, a set of experiments demonstrate verification of three models, along with performance analysis of the impact of the verification, in terms of latency and throughput of the system, showing the efficiency of the approach

Untangling the intricacies of thread synchronization in the PREEMPT-RT linux kernel

This article proposes an automata-based model for describing and validating the behavior of threads in the Linux PREEMPT-RT kernel, on a single-core system. The automata model defines the events and how they influence the timeline of threads' execution, comprising the preemption control, interrupt handlers, interrupt control, scheduling and locking. This article also presents the extension of the Linux trace features that enable the trace of the kernel events used in the modeling. The model and the tracing tool are used, initially, to validate the model, but preliminary results were enough to point to two problems in the Linux kernel. Finally, the analysis of the events involved in the activation of the highest priority thread is presented in terms of necessary and sufficient conditions, describing the delays occurred in this operation in the same granularity used by kernel developers, showing how it is possible to take advantage of the model for analyzing the thread wake-up latency, without any need for watching the corresponding kernel code